Unloading mechanism



H. H. ALDRIGH.

UNLOADING MECHANISM.

APPLiCATlON FILED SEP'LIM, I918. 1,334,828. Patented 2a, 1920..

2 SHEETS-SHEET 2.

.UNITED srnr'ns rnrnnr OFFICE.

I ROSOOE HILTON ALDRICH, OF ALLENTOWN, PENNSYLVANIA, ASSIGNOR TO ALDRICH PUMP COMPANY, OF ALLENTOWN, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIA.

UNLoADING maonamsm.

Specification of Letters Patent.

Patented Mar. 23, 1920.

To all whom it may concern Be it known that I, Roscoe H. ALDRICH, a. citizen of the United States, and a resident of Allentown, in the county of Lehigh and State of Pennsylvania, have invented a new and Improved Unloading Mechanism;

of which the following is a full, clear, and exact description.

The invention relates to pumps and its object is to provide a new and improved unloading mechanism arranged to unload the pump by preventing the pump from pumping water or other fluid to an accumulator or other device as soon as the fluid pumped into the accumulator or other device reaches its maximum. Another object is to cause the pump to pump fluid into the accumulator or other device as soon as the fluid therein drops to a predetermined amount. Another object is to unload triplex or quintuplex or other multiple pumps inwhich the suction valves are sometimes under forced pressure and are raised by the unloading device in unison with the suctionstroke of the pump. I

With these and other objects in view the invention consists of certain novel features of construction as hereinafter shown and described and then specifically pointed out in the claims. 7

A'practical embodiment of the invention is represented in the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

' Figure 1 is a side elevation of the'unloading mechanism as applied to a pump connected with an accumulator and showing the unloading mechanism in normal position with the pump pumping a fluid to the accumulator;

Fig. 2 is asimilar view of the unloading mechanism as applied and with the parts in position to hold'the suction valve open;

Fig. 3 is an enlarged sectional side ele vation of a portion of the unloading device in inactive position relative to the suction valve;

Fig. 4 is a similar view ofthe same with the suction valve raised by the unloading mechanism; and

Fig. 5 is an end elevation of the same with parts in section.

The power pump 10 on which the unloading mechanism is used is of usual construcplainly indicated in Figs. 1 and 2.

' tion and is provided with a" suction pipe 11 and a discharge pipe 12 connected with an accumulator 13 of any approved construction. The suction pipe 11 connects with the, suction valve casing '20 provided with a valve seat 21 opened and closed by a suction valve 22 normally held to its seat by a spring 23 abutting against a cap 21 formmg part of the valve casing 20. hen the pump 10 is running then the suction valve 22 is raised against the tension of the spring 23 by the suction action of the pump cylinder and during the discharge stroke the suc tion valve 22 is moved to its seat by its own weight and that of the spring 23.

In order to hold the suction valve 22 off its seat in open position to prevent the pump from pumping water or other liquid to the accumulator 13, use is made of a lifter rod or stem 30 mounted to slide up and down in a suitable bearing 31 arranged in the valve casing 20. A spring 32 is interposed (between the lower end of the suction valve lower end of the lifter rod 30 is seated on an arm 40 attached to a rock shaft 41 journaled in the valve casing 20 and extending to the outside-thereof, as plainly indicated in Fig. 5. On the outer'end of the rock shaft 41 is secured a weighted arm 42 for .counterbalancing the weight of the suction valve 22. .On the outer end of the rock shaft 41 is also secured an arm 43 adapted to be engaged by stop collars 44 and 45 held spaced on a rod 46 extending loosely at its lower end through the free end of the arm 43. The upper end of the rod 46 is pivotally connected with the arm t? of a bell crank lever 48 fulcrumed at 49 on a bracket 50 attached to the frame of the pump Mai e 'arm' 47 of the bell crank lever 18 is provided with aweight 51 and the other arm 52 of the bell crank lever 48 is adapted lug 53 holding the arm 52 of the bell crank lever 48 in uppermost position while the stop lug 62 is a distance above the bracket 63. When the several parts are in the position shown in Fig. l the lifter rod is in lowermost position to allow the suction valve 22 to function in the usual manner while water or other liquid is pumped into the accumulator .13. When the movable member .64 of the accumulator 13 rises its bracket 63 finally engages the stop lug 62 and lifts the same and with it the weight 61 so that the weight 60 pulls the other end of the flexible connection 55 downward. When the movable member 64 of the accumulator nears its maximum upward travel then the stop lug 54 engages the arm 52 of the bell crank lever 48 and imparts a swinging motion to this bell crank lever, and when the arm 47 of this bell crank lever has passed a vertical position in swinging from the right to the left then this weighted arm causes a quick swinging of the bell crank lever whereby the collar 45 of the rod 46 actuates the arm 43 thereby turning the rock shaft 41. When this takes place the arm 40 lifts the lifterl rod 30 whereby the suction valve 22 is moved upward off its seat 21 and is held in this uppermost open position thus preventing the pump from pumping water or other liquid to the accumulator 13. When the movable member 64 of the accumulator 13 moves downward on the withdrawal of the water from the accumulator then the weight 61 imparts a return movement to the flexible connection 55 whereby the stop lug 53 is moved upward into engagement with the arm 52 of the bell crank lever 48 at the time the movable member 64 nears its lowermost position. 'The stop lug 53 now actu-- ates the bell crank lever 48 for returning the same to the normal position shown in Fig. 1, and this return movement of the bell crank lever 48 causes the rod 46 and its stop lug 44 to act on the arm 43 to turn the rock shaft 41 in thereverse direction thereby swinging the arm 40 downward. This downward movement of the arm 40 allows the lifter rod 30 to move downward whereby the-suction valve 22 is released and permitted to return to its seat 21 to again function in the usual manner during the running of the pump.

From the foregoing it will be seen that by the arrangement described water is pumped the pump is lifted off its seat and held in open position to prevent the pump from pumping liquid to the accumulator. On the withdrawal of the water from the accumulator the movable member 64 moves downward and when it reaches its normal predetermined lowermost position the unloading device releases the suction valve 22 to allow the latter to again function in the usual manner.

Having thus described my invention, I claim as new and desire to secure by Letters Patent :v

1. In an unloading mechanism for a pump having a suction valve, a lifting device normally out of engagement with the suction valve of the pump, said lifting device comprising a counter-balanced mechanism one side of which is adapted to be raised and held by actuating means controlled by the accumulated fluid pumped by the pump, to

cause downward movement of the other side.

of the counter-balanced mechanism for lifting the suction valve and to hold it in lifted or inactive position on the water level reaching a maximum height, the first mentioned side of the counter-balanced mechanism being adapted to be engaged and low-- ered by said actuating means controlled by the accumulated fluid on the level of the fluid dropping to a predetermined level to cause upward movement of the other side of the counter-balanced mechanism, thereby releasing the suction valve and allowing it to drop to active position.

2. In an unloading mechanism for pumps, the combination with the suction valve of the pump, of a lifter rod adapted to engage the said suction valve to lift it off its seat and hold it in lifted position, a rock shaft provided with arms of which one engages the said lifter rod, a weighted lever, a rod pivotallv conected. with the said weighted lever and having spaced stops between which extends the other arm of the said rock shaft, and actuating means for the said weighted lever comprising a counter-balanced mechanism adapted to have one side thereof raised and held on an excess accumulation of the fluid pumped by the pump, to cause downward movement of the other side of the counter-balanced mechanism for moving said weighted lever in one direction, said counter-balanced mechanism being arranged to be moved in the opposite direction on the accumulation of fluid dropping to normal condition for moving said weighted lever in the-opposite direction.

ROSCOE HILTON ALDRICH. 

